What can otolith examination tell us about the level of perturbations of Salmonid fish from the Kerguelen Islands?

Fabien Morat (1) , S. Betoulle (2) , M. Robert (3) , A. F. Thailly (4) , S. Biagianti-Risbourg (2) , R. Lecomte-Finiger (1)

1 BETM - Biologie et écologie tropicale et méditerranéenne [2007-2010]
2 Laboratoire d'Eco-Toxicologie / Vignes et Vins de Champagne-Stress et Environnement - EA 2069
3 CCA - Centre Commun d'Analyses
4 IPEV - L'Institut polaire français Paul-Emile Victor

Otoliths preserve a continuous record of the life cycle from the natal through the adult stage. For that reason, the morphological and chemical characteristics of otoliths of two nonnative Salmonids, brown trout (Salmo trutta) and brook charr (Salvelinus fontinalis) from populations on the Kerguelen Islands were compared. Several approaches were used to study the relationships between otolith morphometry, crystal morph and chemical elemental composition. These salmonids sampled in Kerguelen are well differentiated in terms of species through their otolith shape. The results indicate that ecotypes and river populations can be reasonably well differentiated on the basis of otolith shape. The crystallisation study has revealed the presence of a particular form: the vaterite, present at a high rate: 45% of S. fontinalis and 18% from Salmo trutta fario. Moreover, vaterite and aragonite otoliths presented differences in chemical composition.

Mots clés: salmonidae; Kerguelen Islands; otolith shape; crystallography; ONCORHYNCHUS-TSHAWYTSCHA; VATERITE OTOLITHS; ATLANTIC SALMON; SHAPE-ANALYSIS; POPULATIONS; MORPHOLOGY; CHEMISTRY; ARAGONITE; CALCITE; TROUT

Domaines: Biodiversité et Ecologie

Fabien Morat, S. Betoulle, M. Robert, A. F. Thailly, S. Biagianti-Risbourg, et al.. What can otolith examination tell us about the level of perturbations of Salmonid fish from the Kerguelen Islands?. Ecology of Freshwater Fish, 2008, 17, pp.617-627. ⟨10.1111/j.1600-0633.2008.00313.x⟩. ⟨hal-00691053⟩